Thermostatic switch.



B. JfSMITH. THERMOSTATIC SWITCH. APPLICATION FILED APR.5, 1911.

1,008,870. Patented Nov. 14, 1911.

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' UNITED STATES PATENT OFFICE.

BERT .1. SMITH, or MODESTO, CALIFORNIA, AssreNoR To Hour: CONSTRUCTION coir- PANY, or MODESTO, CALIFORNIA, A conronATIoN or camronnm.

THEimosTATIc swITcH.

Specification of Letters Patent.

Application filed April 5,

tric ovens and other receptacles of like character.

The object of the invention is to provide a thermostatic switch of simple and novel character wherein provision is made for quickly and accurately adjusting the degree of temperature at which theswitch will be opened by itsthermostatic control-.

ling means.

The invention includes the said means,

the switch embodying adjustably related elements, and a means operatively connected to-the thermostatic means for effecting the relative adjustments of the elements of the switch.

An embodiment of the invention is illustrated by way of example, in the accompanying drawings, wherein- Figure 1 is a side elevation of a thermostatic switch conforming to the invention; Fig. 2 is a bottom plan view thereof; Fig. 3 is a perspective view of the-elements of the switch and their appurtenances; and Fig. 4 an elevat'on of the indicating dial by which the adjutments of the switch are determined.

Similar characters of reference designate corresponding parts throughout the several.

of the switch is controlled is designated the numeral 1 and is preferably of the hol low accordion-like diaphragm type, being provided at one end with an anal extension 2 and at its other end with an axial boss 3. The supporting means for the thermostat embodies a plate 4 of insulating material which is attached to an adjacent wall of the structure in connection with which the switch is employed and a bracket 5 which is attached to the said plate 4 and .also to the said boss 3.

The switch comprises two .contact parts, the one, 6, being fixed to the plate 4 and having at its upper end an angular extension 7 for this purpose, and the other, 8, being movable with relation to the contact 6 to close or open the circuit. The contact 6 embodies preferably a single finger which depends from the extension 7 and the contact 8 embodies a clip having resilient legs gage the contact 6. The contact 8 is rigidlyassociated with a member 9 and projects from the rear end of said member. latter is provided with depending-lugs 10 dent of the operation of the switch, adjusting means. 'The said adjusting means includes a stem 13 which is journaled in a wall of the structure in connection with' which the switch is employed and" which at its inner end has a threaded portion 14 that passes through the lug 11, the opening of the latter being also threaded. The stem 13 is also connected at its inner end by a swivel joint 15 to theadjacent end of the extension 2.. The adjusting means also inand which is mounted on the wall of the structure in connection with which the switch is employed and the stem13 passes The v Patented Nov. 14, 1911. 1911. Serial No. 619, 079.

- which are designed to straddle and to enand 11. The extension 2 has asquare cross cludes a dial 16 which is suitably calibrated through said dial and has fixed on its outer end a finger 17 which serves both as an operating lever and as an index pointer, and traverses the dial 16. a j

The extension 7 is'provided with a bind-; ingpost 18 and the member 9 is provided with a binding post. 19.

The extent of range of the threads 14 is considerably greater than that which is nec essary for the adjustment of the contact 8 with relation to the contact 6 and is selected to facilitate the convenient assemblage and the accurate relation of the parts.

The operation of the device should be apparent from the foregoing description. The diaphragm 1 is preferably filled with a suit able liquid for the purpose, such as alcohol, and when it expands it moves the contact 8 forwardly and if its expansion be sufiicient ultimately causes said contact 8 to disengage the contact 6. On the other hand a contraction of the diaphragm 1 will cause a rear ward movement of the contact 8 and will close the circuit. When the diaphragm 1 expands or contracts the extension 2 and the stem 13 move axially as a unit, the member 9 partaking in the movement of said stem and produ'clng the engagement or disengage ment of the contact 8 with relation to the contact 6. The means for adjusting the contacts 6 and 8 with relation to one another is operative to determine the temperature atwhich the circuit will be broken by the thermostat 1. It is apparent that if the con contact 8. To "carry out this function the stem 13 is turned, the finger- 17 being manipulated as a lever for this purpose and in accordance with the turning movement of the stem 13 the member 9 is moved forwardly or rearwardly, as the case may be, through a corresponding extent. The degree of turning movement of the stem 13 and consequently the degree of movement of the member 9 and the normal position of the contact 8, corresponds to the-extent through which the finger 17 is moved with relation to the dial 16. The reading on the dial corresponding to the position that the finger 17 occupies when its movement is terminated indicates the degree of temperature at which the contact 8 will disengage the contact 6.

Thus in Fig. at the finger 17 overlies the.

reading 100 and indication is thereby given that the contact 8 is so positioned with relation to the contact 6 that when a temperature of 100 is attained disengagement of said contact-s will take place.

N o specific description herein contained is intended to put any limitation upon the appended claims which does not inhere in the language thereof.

Having fully described my invention, I claim:

1. In a device of the type set forth, in

combination, a switch embodying a fixed contact and a contact movable into and out of engagement with the fixed contact, a member carrying the movable contact and provided with depending lugs, one of which has a square aperture and the other a threaded aperture, a stem having a threaded portion engaged through the-threaded aperture, a thermostat having an extension of square cross section engaged through the square aperture, a swivel connection between the extension and the stem, a manually operated finger fixed on'the outer end of the stem,-

and a scale-arranged to be traversed by the finger.

2. In a device of the type set forth, in

combination, a thermostat having an extension, a rotatable threaded stem, a switch embodying a fixed contact and a movable contact, and a member carrying the movable contact and having a lu-g which surrounds and engages the stein, the stem being connected to the extension, the member also having a lug which is non-rotatably associated with the extension.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

BERT J. SMITH. 

